Western lowland gorilla

Scientific name: Gorilla gorilla gorilla

Country: Cameroon, Gabon, The Congo, Democratic Republic of Congo, Central African
Republic, Nigeria, Angola, Equatorial Guinea

Continent: Africa

Diet: Leaves - folivore, fruits - frugivore their diet consists of vegetation, some fruits, and nuts. They will also eat invertebrates such as termites. In the morning they forage and eat for about two hours, and then they rest until the afternoon, when they start to eat again until twilight. In the Zoo, they are given a wide variety of vegetables, fruit, nuts, eggs, branches and a commercially-made "Primate Diet" biscuit. Besides constant fresh water being available for drinking, they are given sugar-free Ribena and herbal tea.

Food & feeding: Herbivore

Habitats: Tropical rainforest

Conservation status: Critically endangered

Relatives: Chimpanzee, orang utan, man

Description: Large ape, covered in black hair. The face is bare black skin as is the chest. The hair on the back of mature males becomes silvery with age hence the name 'silverback'. The head has a short muzzle, large ridges above the eyes and a mass of fat and gristle on top of the head, particularly in males. The fingers and toes each have nails. When walking, gorillas walk on the soles of their feet and the knuckles of their hands, although they can walk a few metres standing on their legs alone.

Lifestyle: Gorillas are active during the day. They wake at dawn and feed for a few hours, choosing juicy leaves and shoots which they pick and peel with their hands, usually while sitting down. During the heat of the day the group dozes, digesting the morning's meal until perhaps 2:00pm. They are then on the move again and feeding until bedding down for the night just before sunset. Beds are simply a mat of nearby vegetation thrown together to form a cosy nest. They prefer to live in areas where there is a mass of low-level juicy vegetation: old river beds, old clearings or areas affected by landslides. We usually think of gorillas as living on the ground, but they are well able to climb trees and females and youngsters may choose to sleep in trees.

Family & friends: Gorillas are sociable and have a very structured family life, consisting of one dominant silverback male that will drive out other mature males from the group as they mature. Females have a pecking order that seems to be determined by how long the females have been part of the group. Usually groups contain about five animals. They do not defend their home territory and often overlap with other groups, although groups try to steer clear of one another.

Keeping in touch: The dominant male makes most of noise! He has a range of calls that alert the group of approaching predators. His chest-drumming display can be heard a couple of kilometres away. This display serves to keep neighbouring groups out of sight of one another. If they do meet, the males may smash plants around, charge and beat their chests in a display of strength. The females are rather quieter, with a vocabulary of grunts and grumbles.

Growing up: A female gorilla can live up to 40 years and may produce up to 10 young in her lifetime. Of these perhaps only two or three will survive to maturity. Like human children, the young require years of care and attention before they are able to take their place in gorilla society. Females are sexually mature at 10 years of age, whereas males mature later at 15 years.

Male gorillas splash-out. Even though they are not good swimmers, they launch themselves into swampy pools, making a huge splash as they do so. The splashes are a signal of strength to other gorillas in or near the pools, the bigger the splash the bigger the silverback.

Conservation news: The wild population of Western lowland gorillas is estimated somewhere between 90,000 and 110,000, but this could be a big over estimate. Many gorillas are killed for the 'bush meat' trade where animals are shot by hunters and the meat sold to traders in towns and cities. The ebola virus is also causing problems for the remaining populations.